Muffler



(No Model.)

G. W. SHIPMAN.

MUFFLER.

No. 425,637. Patented Apr. 15, 1890.

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IEORGE IV. SIIIPMAN, OF TERRE HAUTE, INDIANA.

MUFFLER.

SPECIFICATION forming part of Letters Patent No. 425,637, dated April 15, 1890.

Application led November 26, 1889: Serial No. 331,647. (No model.)

T0 a/ZZ wwm/ t may concern:

Be it known that l, GEORGE IV. SHIPMAN, a citizen of the United States, residing at Terre Haute, in the county of Vigo and State of Indiana, have invented a new and useful Improvement in Mufflers, of which the following is a specification.

My invention relates to an appliance for deadening or mui-lling the sound of discharging v[luid under pressure.

My improvement is useful for its purpose in various connections in which it is desirable to prevent noise occasioned by compressed vfluid in discharging, as discharging steam or air; and I desire to be understood as claiming it for all the various connections in which it is capable of such use. The particular purpose, however, for which I design my improved mufiler is for use in connection with the airbrakes on railway cars, and more especially on sleeping-cars, to prevent the sound, so disturbing and annoying to passengers, of the compressed air in discharging to release the brakes from its effect.

In the accompanying drawings, Figure l shows my improved muffler in about twothirds of its actual size in sectional elevation; and Fig. 2 is a similar view of a modified form of the muffler.

The preferred construction of the apparatus is that illustrated in Fig. l and comprising a metal shell A, preferably of cylindrical shape, and having a flat base A, provided at its een` terwith a flanged orifice B, internally threaded to adapt it to be screwed upon the nozzle of the escape-pipe leading from the compressedair mechanism underneath a car. The shell A, which thus constitutes the body portion of the muffler, is surmounted by a cover C, preferably hemispherical or substantially hemispherical, formed of an external perforated wall o" and an internal perforated wall 0", having the space between the two closed around the base of the cover, where the latter is secured, as shown, to the sides of the body porF tion A, and the space between the walls is filled with a yielding and porous substance D, such assponge The cover or crown C may be further strengthened by a bolt q, passed perpendicularly through its apex and through a shield @,vbeing incloscd in the interposed sleeves q and Q2. The shield p extendsover the crown from brackets o at the sides ofthe body portion A, and it is imperforate and protects the apparatus from access to it from without of foreign matter. The shape thus described of the shell (including the cover) of the apparatus, while preferred, may be de parted from without departing from my invention.

lVithin the body portion A of the muffler are two concentric chambersE and F, the wall of the former being perforated around its base and that of the latter around its top, andboth chambers E and F are provided with a common cover u, secured in place by headed rods m, passing through it and through the base A where'they are fastened by nuts l, which also serve to clamp the walls of the chambers E and F between their cover and the said base. The chamber F surrounds the inletopening B.

In the use of the muffler constructed as thus described the escaping compressed air discharges, first, into the chamber F, thence into the chamber E,and,iinally,into the chamber afforded around the chamber E by the cylinder A, whence it escapes through the crown (l. As will be seen, the compressed air, entering successively the chambers F, E, and A, gradually expands toward its eventual outlet through the perforated crown, thereby graduating the suddenness and force of its eXpansion,and whatever expansive power may still be retained by it when it reaches the outermost chamber in the cylinder A will be rendered noiseless in its action by impingement against the sponge D in the path to the eventual outlet.

The number of chambers E F inside the body portion A may be increased or diminished without departing from the spirit of my invention, so long as they are rendered successively intercommunicating and permit the gradual out-ward expansion from one to the other of the discharging compressed fluid.

In Fig. 2 the interior of the muffler is not divided into the successively-enlarging series of intercommunicatin g chambers, but instead has the perforated double wall of the cover C extended some distance into the body portion A and `filled throughout with sponge D or analogous material. In this form of the device, which is not considered so desirable as that illustrated in Fig. l, the mu'li'ling effeet is produced by the deadening action of the sponge D upon the iiuid discharging through the inlet B and expanding within the muffler in passing through the perforations in the device.

W' hat I claim as new, and desire to secure by Letters Patent, is-

l. A muiiier having its shell provided with an inlet-opening B and formed with a cover comprising a double perforated Wall filled in the intermediate space with a yielding porous substance D, and chambers F and E, the one within the other inside the said shell around the inlet-opening, the chamber F communicating through its upper end with the chainber E, and the chamber E from its lower end with the interior of the shell, substantially as and for the purpose set forth.

2. A muffler comprising, in combination, a cylindrical body portion A, having an inletopeniug 13 in its base and containing concentric intercommunicating chambers F and E, having a 'common cover n and perforated, respectively, near their upper and lower ends an d 'surroundin g the inlet-opening, and a substantially-hemispherical shielded crown C, secured to the body portion A and formed with a double perforated wall filled in the inten mediate space with sponge D or the like, substantially as and 'for the purpose set forth.

J. XV. DYRENFORTH, M. J. Fnos'r. 

